NAND flash memory is an attractive media for primary storage in various space applications thanks to its excellent properties such as high density, low power consumption and random access. A necessary step to determine if a NAND flash memory is suitable for a specific space application is to test its reliability against radiation. In the scenarios where flash components must survive high radiation levels such as GEO orbits and other deep space trajectories, radiation hardened NAND flash memory is used. The thin (8 nm) tunnel oxides and high internal on-chip voltages (18-20V) make radiation hardening NAND flash memories very challenging. Nevertheless, many useful space missions (LEO, some Mars missions, etc.) only require a reduced level of radiation tolerance, often less than 50 k rad. Therefore, it is possible to use conventional commercial NAND flash memory to achieve high storage density with low cost in severe service environments, such as outer space applications including GEO orbits and deep space trajectories.